Effect of bias voltage on the structure and hardness of TiSiN composite coatings synthesized by cathodic arc assisted middle-frequency magnetron sputtering

TiSiN nanocomposite coatings were synthesized by using an industrial scale cathodic arc assisted middle-frequency magnetron sputtering system. The influence of substrate bias voltage on the microstructure, hardness, and surface morphology was investigated. Specifically, the composite coatings prepared at an optimized bias voltage of 150 V were found to be nc-TiN/a-Si3N4 structure with TiN crystalline grain sizes ranging from 8 to 15 nm and exhibit a hardness of 40 GPa and roughness of 4 nm.